Even though I can't get a therapist to help me transition yet due to my parents views conflicting with mine, I want to know a bit about therapy sessions.

What sort of questions will they ask? Are they trying to figure out if you pass for hormone therapy? Will they criticize you?

If anyone can share some of their experiences, good or bad, with me, that would be great!

Where do you live .... i know several places that you can see a counselor underage without your parents knowledge or consent.  Ask your guidance counselor for help.

The therapist is there to help you ...so they should never make fun or you or criticize you ... each therapist does things a little different according to their style.  My therapist started the first session asking why I was there and what I wanted -- I said straight up that I wanted the lettter to start hormones & the next session we began working on the letter.  She asked question of when did I start trying to present myself as a male ... when did I know something was different... honestly I never put words to my own gender identity until a year before I started therapy....I lived my life as a masculine lesbian.  That didn't stop my therapist from writting the letter - she believes everyone walks their own journey and finds their way in their own time.

Most of the time in therapy was spent working on my relationship with my wife to make sure it continued once I started changing. 

Therapy shouldn't be something to be fearful of -- the right therapist can validate you and make you feel better about yourself.

My therapist doesn't ask me too much after our first session. She really just wants to get a well rounded view of my life and how I handle certain situations. I've asked her to provide a little more guidance in terms of questioning, but she's very adamant about me just talking about what's on my mind. Therefore, in advance I kind of prepare what I want to talk about that day. Since I have a timeline for when I was my surgery letter, I make sure to vary the topics so she feels like she has discussed a broad spectrum of my life with me.